Arc-Second Pointer for Balloon-Borne Astronomical Instrument

A control system has been designed to keep a balloon-borne scientific instrument pointed toward a celestial object within an angular error of the order of an arc second. The design is intended to be adaptable to a large range of instrument payloads. The initial payload to which the design nominally applies is considered to be a telescope, modeled as a simple thinwalled cylinder 24 ft (7.3 m) long, 3 ft (0.91 m) in diameter, weighing 1,500 lb (having a mass of 680 kg).